Welcome to FT. Where is your home airport and what city in Europe do you prefer to fly into? Once you narrow down your city pairs I'd look at Orbitz or Kayak to see which airlines have flts that suit you. After you narrow down an airline then you can pick credit cards that will achieve your goal. With Chase UR you can transfer to UA, KE, BA and a couple of others. Maybe you want to fly with DL, so you'd look at Chase UR (to KE) & Amex DL cards. Give us some more info please.